In consideration that there has been paucity of data regarding the clinicopathological significance of the PTEN loss in DLBCL; and that PTEN was the well-established inhibitor of PI3K/AKT signaling pathway [8], we’ve extended the detection of genetic change from PIK3CA to PTEN on DNA level using FISH approach. The gene discussed is PTEN; the disease is diffuse large B-cell lymphoma.